import type { TileAssignment, TileScene } from '@/src/types/tiles';

export type TileSetConfig = {
  sceneId: string;
  grid: {
    cols: number;
    rows: number;
  };
  mode: 'single' | 'random';
  tiles: TileAssignment[];
};

export function createEmptyAssignments(scene: Pick<TileScene, 'cols' | 'rows'>): TileAssignment[] {
  const assignments: TileAssignment[] = [];
  for (let row = 0; row < scene.rows; row += 1) {
    for (let col = 0; col < scene.cols; col += 1) {
      assignments.push({ row, col, designId: null });
    }
  }
  return assignments;
}

export function applySingleDesign(
  assignments: TileAssignment[],
  designId: number | null,
): TileAssignment[] {
  return assignments.map((tile) => ({ ...tile, designId }));
}

export function randomizeAssignments(
  scene: Pick<TileScene, 'cols' | 'rows'>,
  designIds: number[],
): TileAssignment[] {
  if (designIds.length === 0) {
    return createEmptyAssignments(scene);
  }
  const assignments: TileAssignment[] = [];
  for (let row = 0; row < scene.rows; row += 1) {
    for (let col = 0; col < scene.cols; col += 1) {
      const randomIdx = Math.floor(Math.random() * designIds.length);
      assignments.push({ row, col, designId: designIds[randomIdx] });
    }
  }
  return assignments;
}

export function countTilesPerDesign(assignments: TileAssignment[]): Record<number, number> {
  const counts: Record<number, number> = {};
  for (const tile of assignments) {
    if (tile.designId == null) continue;
    counts[tile.designId] = (counts[tile.designId] ?? 0) + 1;
  }
  return counts;
}

export function tileKey(row: number, col: number): string {
  return `${row}-${col}`;
}

// Alias for readability if needed elsewhere
export const initAssignments = createEmptyAssignments;

export function getTileVariation(row: number, col: number) {
  const seed = (row + 1) * 17 + (col + 1) * 31;
  const rand = Math.sin(seed) * 10000;
  const value = rand - Math.floor(rand);
  const rotateDeg = (value - 0.5) * 0.8; // ~ -0.4° to +0.4°
  const scale = 1 + (value - 0.5) * 0.02; // +/- 1%
  return { rotateDeg, scale };
}

export function buildConfig(
  sceneId: string,
  scene: Pick<TileScene, 'cols' | 'rows'>,
  mode: 'single' | 'random',
  tiles: TileAssignment[],
): TileSetConfig {
  return {
    sceneId,
    grid: {
      cols: scene.cols,
      rows: scene.rows,
    },
    mode,
    tiles,
  };
}